Nanoparticle infiltration to prepare solvent-free controlled drug delivery systems (original) (raw)
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Acta Scientific Pharmaceutical Sciences, 2021
Background: As the lamotrigine is poorly water soluble drug. The dug was characterized for different physico-chemical properties and nanosized by solvent evaporation sonication technique. Aims and Objectives: This research was aimed to reduce the model particle size and evaluate the diffusion study. Methods: In the research work the bath sonication was done at 250 hertz frequency at room temperature. During sonication 25ml of purified water as added slowly drop by drop till turbidity was observed. The obtained residue was then centrifuged for 30 minutes at 4000 rpm for complete recovery of nanosized drug. Results: Lamotrigine was found to be very soluble in methanol, soluble in phosphate buffer pH7.4 solution. It was found to be sparingly soluble in 0.1MHCl, phosphate buffer, pH 5.8 solutions. The nanosizing of drug particle was confirmed when the number of sonication cycles was increased up to 15 cycles as optimized, the %transmittance was found to increase proportionally. Conclusion: This diffusion was in significant amount and confirmed that the nanosized drug easily pass through the biomembrane and can be targeted to desired sites in significant amount.
Study of the Drug Diffusion Through Polymeric Membranes
Revista de Chimie
We present the studies carried out on the transport properties of some membranes obtained from synthetic polymers: polyurethane and ethylene-vinyl acetate copolymer, for use in the development of transdermal therapeutic systems with limiting membranes of speed. The properties of drug active substances transport through membranes were highlighted by performing studies with a diffusion cell. Experimental drug active substances were paracetamol and tetracycline. The experimental data obtained was processed using a general mathematical model for drug release from non-porous, non-swellable transdermal devices, which starts from Fick�s second law and has terms that also take into account the possibility of retaining the drug in the membrane polymer. Even though the mathematical model does not take into account neither the swelling phenomenon nor the possibility of membrane erosion, a good agreement between model and experimental data was obtained. The values of effective diffusion coeffic...
In Vitro Dissolution Studies of Nanopharmaceuticals in Drug Delivery System
Iosr phr, 2022
Nanopharmaceuticals represent an emerging field where the sizes of drug particles or a therapeutic delivery system work at the nanoscale. Nanotechnology can offer the advantages of increasing solubility and bioavailability of delivering drugs. Nearly 40% of drugs coming to the market nowadays are having poor solvency-related issues and 70% of molecules in the discovery are in effect fundamentally insoluble in water, a long-standing issue is the difficulty of delivering the appropriate dose of a particular active agent to the specific disease site. The poor solubility of many drugs along with a slow dissolution rate is a major research and industrial problem for pharmaceutical scientists and industries. Nanopharmaceuticals have enormous potential in addressing this failure of traditional therapeutics which offers site-specific targeting of active agents. Such precision targeting via nanopharmaceuticals reduces toxic systemic side effects, resulting in better patient compliance. The present work aimed to prepare and develop chlorothiazide (CTZ) and Lisinopril nanoparticles for rapid and complete release by nano techniques to solve the problem of poor water solubility and bioavailability.CTZ and Lisinopril nanoparticles have to prepare by solvent evaporation method under an ultra-sonication process. Prepared nanoparticles were evaluated for yield, drug loading, and entrapment efficiency studies.CTZ and Lisinopril nanoparticles are to be characterized for drug and polymer interaction by using FT-IR and DSC. The morphological characteristics of the formulation can be studied. In vitro drug dissolution study of a drug, diffusion has to be performed by using the Dissolution and Disintegration apparatus, and Drug-like properties, Molecular properties, and Biological activity scores are calculated.
Evaluation and Prediction of Drug Permeation
Journal of Pharmacy and Pharmacology, 1999
A major challenge confronting the pharmaceutical scientist is to optimize the selective and ef®cient delivery of new active entities and drug candidates. Successful drug development requires not only optimization of speci®c and potent pharmacodynamic activity, but also ef®cient delivery to the target site. Following advances in rational drug design, combinatorial chemistry and high-throughput screening techniques, the number of newly discovered and promising active compounds has increased dramatically in recent years, often making delivery problems the rate-limiting step in drug research. To overcome these problems, a good knowledge of the pharmacokinetic barriers encountered by bioactive compounds is required. This review gives an overview of the properties of relevant physiological barriers and presents some important biological models for evaluation of drug permeation and transport. Physicochemical determinants in drug permeation and the relevance of quantitative and qualitative approaches to the prediction and evaluation of passive drug absorption are also discussed.
Biomolecules
The goal of this work was to comprehensive study the transport properties of controlled-release systems for the safe and reliable delivery of drugs. Special emphasis has been placed on the measurement of the diffusion of drugs, alone or in combination with carrier molecules for enhanced solubility and facilitated transport. These studies have provided detailed comprehensive information-both kinetic and thermodynamic-for the design and operation of systems for the controlled release and delivery of drugs. Cyclodextrins are among the most important carriers used in these systems. The basis for their popularity is the ability of these materials to solubilize poorly soluble drugs, generally resulting in striking increases in their water solubilities. The techniques used in these investigations include pulse voltammetry, nuclear magnetic resonance (NMR) and Raman spectroscopy, ultrasonic relaxation, and dissolution kinetics. Transport in these systems is a mutual diffusion process involving coupled fluxes of drugs and carrier molecules driven by concentration gradients. Owing to a strong association in these multicomponent systems, it is not uncommon for a diffusing solute to drive substantial coupled fluxes of other solutes, mixed electrolytes, or polymers. Thus, diffusion data, including cross-diffusion coefficients for coupled transport, are essential in order to understand the rates of many processes involving mass transport driven by chemical concentration gradients, as crystal growth and dissolution, solubilization, membrane transport, and diffusion-limited chemical reactions are all relevant to the design of controlled-release systems. While numerous studies have been carried out on these systems, few have considered the transport behavior for controlled-release systems. To remedy this situation, we decided to measure mutual diffusion coefficients for coupled diffusion in a variety of drug-carrier solutions. In summary, the main objective of the present work was to understand the physical chemistry of carrier-mediated transport phenomena in systems of controlled drug release.
Journal of Controlled Release, 1999
The purpose of this study was to define membrane controlling factors responsible for drug release from a controlled-porosity osmotic pump tablet (OPT) that utilizes a sulfobutyl ether-beta-cyclodextrin, (SBE)(7m)-beta-CD, as both a solubilizing and osmotic agent. The OPT was spray coated with cellulose acetate solutions varying the amount and size of micronized lactose, the amount of triethyl citrate (TEC) and the composition ratio of dichlormethane to ethanol. Chlorpromazine (CLP) was used as a model drug. The release of CLP from the OPTs was studied using the Japanese Pharmacopoeia dissolution method. The membrane surface area of the OPTs were measured with multi-point analysis by the gas absorption method. The release rate of CLP from OPTs containing (SBE)(7m)-beta-CD increased with increasing amounts of micronized lactose and decreasing amounts of TEC and lactose particle size in the membrane. Also, the CLP release rates from the spray-coated OPTs using mixtures of varying ratios of dichlormethane to ethanol were almost identical. The membrane surface area of the OPTs following release of membrane components had a linear relationship to CLP release rates from the OPTs. The present results confirmed that the membrane controlling factors responsible for the drug release were the amount and size of micronized lactose and the amount of TEC in the membrane.
Dacarbazine (Dac) is one of the most commonly used chemotherapy drugs for treating various cancers. However, its poor water solubility, short half-life in blood circulation, low response rate and high side effect limit its application. This study aimed to improve the drug solubility and prolong drug release by developing nanostructured lipid carriers (NLCs) for Dac delivery. The NLC and Dac-encapsulated NLC were synthesized with precirol ATO 5 and isopropyl myristate as lipids, tocopheryl polyethylene glycol succinate, soybean lecithin and Kolliphor P 188 as co-surfactants. The NLCs with controlled size were achieved using high shear dispersion following solidification of oil-in-water emulsion. For Dac encapsulation, the smallest NLC with 155 ± 10 nm in size, 0.2 ± 0.01 polydispersion index and -43.4 ± 2 mV zeta potential was selected. The resultant DLC-Dac possessed size, polydispersion index and zeta potential of 190 ± 10, 0.2 ± 0.01, and -43.5 ± 1.2, respectively. The drug encapsulation efficiency and drug loading were 98.5 % and 14 %, respectively. In vitro drug release study showed a biphasic pattern, with 50 % released in the first 2 h, and the remaining released sustainably for up to 30 h. This is the first report on the development of NLC for Dac delivery, implying that NLC could be a new potential candidate as drug carrier to improve the therapeutic profile of Dac.
Pharmaceutical Retention Mechanisms by Nanofiltration Membranes
Environmental Science & Technology, 2005
This study investigates the retention mechanisms of three pharmaceuticals sulfamethoxazole, carbamazepine, and ibuprofen by nanofiltration (NF) membranes. Laboratory-scale experiments were carried out with two well-characterized NF membranes, with the goal of relating pharmaceutical retention behavior to membrane characteristics, physicochemical properties of the pharmaceutical molecules, and solution chemistry. Results show that retention of pharmaceuticals by a tight NF membrane is dominated by steric (size) exclusion, whereas both electrostatic repulsion and steric exclusion govern the retention of ionizable pharmaceuticals by a loose NF membrane. In the latter case, speciation of pharmaceuticals may lead to a dramatic change in retention as a function of pH, with much greater retention observed for ionized, negatively charged pharmaceuticals. For uncharged pharmaceutical species, intrinsic physicochemical properties of the pharmaceutical molecules can substantially affect their retention. In its neutral form, ibuprofen adsorbs considerably to the membrane because of its relatively high hydrophobicity. Similarly, polarity (represented by the dipole moment) can influence the separation of molecules that are cylindrical in shape as they can be directed to approach the membrane pores head on due to attractive interaction between the molecule polar centers and fix charged groups on the membrane surface. This phenomenon is probably inherent for high dipole moment organic compounds and the governing retention mechanism remains steric in nature.
Journal of Pharmaceutical Sciences, 2009
The purpose of this work is to delineate the release mechanisms of a sparingly water-soluble drug, prednisolone (PDL), from a microporous or controlled porosity-osmotic pump pellet (CP-OPP) using sulfobutylether-b-cyclodextrin (CD) as both a solubilizing and osmotic agent. All factors, osmotic and diffusional, influencing drug release as described by the Theeuwes and Zentner equation were partially demonstrated in an earlier paper 1 and are further quantitatively evaluated here to determine whether the equation may be applied to CP-OPPs. The PDL release rate from the CP-OPPs containing precomplexed PDL follows the zero-order kinetics for up to 30-40% of drug release during the first 1-2 h and subsequently nonzero order kinetics. The zero-order drug release phase reveals the main contribution is from osmotic pumping with a negligible diffusion component, resulting from the nearly constant driving forces in the system. The nonzero order drug release phase is associated with the dynamic changes in the system (e.g., declining osmotic driving force and greater diffusion component with time). In addition, the parameters related to membrane characteristics were determined, and the effect of viscosity was evaluated for the pellet system. The membranes coated on the CP-OPPs are less permeable to water or solutes than the membranes coated on the previously reported tablets. The viscosity due to the CD decreases as a function of CD concentration, which partly affects the observed drug release profiles. The viscosity effect of CD is significant and captured in a hydraulic permeability term.